[Prevention and multimodal therapy of hyperthyroidism]

Enlarged left atrium and decreased left atrial strain are associated with atrial fibrillation in patients with hyperthyroidism irrespective of conventional risk factors

The purpose of this study was to investigate factors associated with AF in patients with hyperthyroidism beyond heart failure (HF), coronary heart disease (CHD), or valvular diseases. A total of 136 patients (mean age, 52 ± 15 years; 86 [63%] female) who were diagnosed with hyperthyroidism for the first time were enrolled. Patients who had HF, CHD, or significant valvular diseases were excluded. Patients were classified into two groups according to the presence (group 1, n = 40) and absence of AF (group 2, n = 96). AF occurred in 40 (29%) patients and 23 (58%) of these patients showed paroxysmal AF. Among the symptoms of hyperthyroidism, the most common chief complaint was palpitation (30%). Advanced age, presence of prior cerebrovascular events, and presence of palpitations were associated with AF. Larger left atrial volume index (LAVI), increased left ventricular mass index, and decreased left ventricular ejection fraction (LVEF) and S' velocity were associated with AF. Among them, presence of palpitations and increased LAVI were independently associated with the occurrence of AF. In addition, strain analysis, decreased LA expansion index (EI), ejection fraction (EF), peak atrial longitudinal strain, contraction strain, and late diastolic strain rate (A sr) and systolic strain rate (S sr) were associated with the occurrence of AF and LAVI. Presence of palpitations and enlarged left atrium were associated with the occurrence of AF in patients with hyperthyroidism irrespective of conventional risk factors. Additional LA analysis revealed that decreased LA function was associated with AF and enlarged left atrium.

Frequency of Cardiovascular Manifestation in Patients With Hyperthyroidism

Introduction Cardiovascular manifestations are very common in hyperthyroidism. Various cardiovascular symptoms such as palpitations, exercise intolerance, dyspnea, angina, edema, and congestive heart failure are commonly reported in hyperthyroidism. In this study, we determine the frequency of cardiovascular signs, symptoms, and various conduction disorders associated with hyperthyroidism. Methodology This cross-sectional, observational study was conducted in the cardiology department of a tertiary care hospital in Pakistan in close association with the internal medicine department from August 2019 to December 2019. A total of 100 hyperthyroid patients confirmed based on thyroid stimulating hormone (TSH, also known as thyrotropin), free T₄ (FT₄; thyroxine), and free T₃ (FT₃; triiodothyronine) were enrolled in the study. Results The most common cardiovascular symptom in this study was palpitations identified in 72% of the participants, followed by breathlessness in 41% of the participants. The most common cardiovascular sign was a pulse rate of more than 100 beats per minute found in 72% of the participants. The most common abnormality in electrocardiogram (ECG) was sinus tachycardia in 39% of the participants, followed by atrial fibrillation in 22% of the participants. In echocardiography, 5% of the participants had systolic dysfunction. Conclusion In this study, cardiovascular signs, symptoms, ECG, and echo changes were very frequent in hyperthyroidism. Management of hyperthyroidism should include routine ECG and echo testing, and cardiologists should be involved in thorough cardiovascular examination.

Hyperthyroidism and cardiovascular complications: a narrative review on the basis of pathophysiology

Cardiovascular complications are important in hyperthyroidism because of their high frequency in clinical presentation and increased mortality and morbidity risk. The cause of hyperthyroidism, factors related to the patient, and the genetic basis for complications are associated with risk and the basic underlying mechanisms are important for treatment and management of the disease. Besides cellular effects, hyperthyroidism also causes hemodynamic changes, such as increased preload and contractility and decreased systemic vascular resistance causes increased cardiac output. Besides tachyarrythmias, impaired systolic ventricular dysfunction and diastolic dysfunction may cause thyrotoxic cardiomyopathy in a small percentage of the patients, as another high mortality complication. Although the medical literature has some conflicting data about benefits of treatment of subclinical hyperthyroidism, even high-normal thyroid function may cause cardiovascular problems and it should be treated. This review summarizes the cardiovascular consequences of hyperthyroidism with underlying mechanisms.